Robert M. Gary wrote:
I'm not sure if the FAA recognizes ground-only operations as a separate
type of solo.

The FAA doesn't but sometimes the question comes down to insurance.

The insurance companies are the de-facto regulatory agency these days.

Your post got me interested so I checked my AIG policy. It only limits
what pilots (and qualifications) can fly the plane. For helicpoters
they define flight as many self-propelled movement, but for fixed wing
they define it as leaving the ground. I know the airlines have training
they require of employees before they can move a plane, something
probably directed by insurance.

Heck, I don't care if the FAA *and* the insurance company allows it.
If I owned something worth the better part of $100 Million, I sure
would want anybody moving the thing to have some sort of training.
Hangar rash gets real expensive real quick when you're talking 777's.